The current invention has been developed particularly to solve the problem of closing a chain loop, i.e. mutually connecting the two ends of a chain after that the chain has been arranged around the chain rings and the sprocket assembly of a bicycle. In particular, the present invention has the object of solving the problem due to the damage of the pin during insertion thereof within the aligned holes of the inner and outer plates of a chain.
U.S. Pat. No. 4,494,945 describes an articulation pin for a chain, having a guide portion connected to a pin body by means of a narrow section. The insertion of the pin body within the aligned holes of the inner and outer plates of the chain is carried out by applying a drawing force to the guide element by tightening a nut which engages a threaded portion of the guide element. The guide element is separated from the pin body by breaking the narrow connecting section at the end of the inserting operation of the pin body.